KR102324006B1 - System and method for mixing tempering air with flue gas for hot scr catalyst - Google Patents

Abstract

A simple-cycle gas turbine system includes an injection system comprising a plurality of injection tubes capable of injecting a fluid into a duct of an exhaust treatment system capable of treating exhaust gases produced by a gas turbine engine. The exhaust treatment system includes a selective catalytic reduction (SCR) system, which can reduce the level _{of nitrogen oxides (NO x ) inside the exhaust gas;} and a mixing system disposed adjacent the plurality of injection tubes and within the exhaust treatment system. The mixing system may swirl the fluid, or the exhaust gas, or both, in a first vortex direction, to promote turbulence along an axis of the exhaust treatment system and thereby to enable mixing between the fluid and the exhaust gas. a mixing module, comprising a plurality of turbulence generators.

Description

SYSTEM AND METHOD FOR MIXING TEMPERING AIR WITH FLUE GAS FOR HOT SCR CATALYST

FIELD OF THE INVENTION The subject matter disclosed herein relates to turbine systems and, more particularly, to exhaust gas treatment.

Gas turbine systems typically include at least one gas turbine engine, including a compressor, a combustor, and a turbine. The combustor is configured to combust a mixture of fuel and compressed air to produce hot combustion gases, which in turn drive the blades of the turbine. Exhaust gas produced by a gas turbine engine may contain certain by-products, such as _{nitrogen oxides (NO x} ), sulfur oxides (SO _x ), carbon oxides (CO _{x ), and unburned hydrocarbons.} . In general, it is desirable to remove or substantially reduce the amount of such by-products in the exhaust gas before it exits the gas turbine system.

Corresponding specific embodiments of the originally claimed invention and scope are outlined below. These examples are not intended to limit the scope of the claimed invention, but rather these examples are merely intended to provide a concise overview of possible forms of the invention. Indeed, the present invention may encompass various forms, which may be similar to or different from the embodiments set forth below.

In a first embodiment, a simple-cycle gas turbine system comprising a plurality of injection tubes capable of injecting a fluid into a duct of an exhaust treatment system capable of treating exhaust gases produced by a gas turbine engine. includes The exhaust treatment system includes a selective catalytic reduction (SCR) system, which can reduce the level _{of nitrogen oxides (NO x ) inside the exhaust gas;} and a mixing system disposed adjacent the plurality of injection tubes and within the exhaust treatment system. The mixing system may swirl the fluid, or the exhaust gas, or both, in a first vortex direction, to promote turbulence along an axis of the exhaust treatment system and thereby to enable mixing between the fluid and the exhaust gas. a mixing module, comprising a plurality of turbulence generators.

In a second embodiment, a simple-cycle large gas turbine system includes a mixing system disposed within an exhaust treatment system of the simple-cycle large gas turbine system. The mixing system includes a first disposed and configured within the exhaust treatment system to swirl, in a first vortex direction, cooling air, an exhaust stream produced by a large gas turbine engine of the simple-cycle large gas turbine system, or both. a first mixing module comprising a plurality of turbulence generators; and a second mixing module comprising a second plurality of turbulence generators capable of swirling the cooling air, the exhaust stream, or both, in a second vortex direction.

In a third embodiment, a method of treating exhaust gas in a simple-cycle gas turbine system comprises: flowing an exhaust stream from a gas turbine engine into a transition section of the exhaust treatment system; injecting cooling air into a flow of exhaust stream in the transition section using an air injection system comprising a plurality of air injection tubes capable of injecting the cooling air; and swirling the exhaust stream, or cooling air, or both, within a transition section of the exhaust treatment system, using a mixing system having an arrayed population of mixing modules. each mixing module of the array population of mixing modules comprises a plurality of turbulence generators capable of swirling the exhaust stream, cooling air, or both, in a first direction, a second direction, or both; and swirling the exhaust gas, air, or both mixes the exhaust stream and cooling air inside the exhaust treatment system to produce cooled exhaust gas and facilitates heat transfer between the exhaust stream and the cooling air . The method also includes directing the cooled exhaust gas to a selective catalytic reduction (SCR) system, and using the SCR system to reduce the level of _{nitrogen oxides (NO x ) in the cooled exhaust gas.}

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present invention will be better understood when the detailed description that follows is read with reference to the accompanying drawings in which like numbers indicate like parts throughout:
1 is a block diagram of a gas turbine system including a mixing system configured to mix exhaust gas with cooling air within an exhaust treatment system, in accordance with an embodiment of the present disclosure;
FIG. 2 is the exhaust of FIG. 1 with a plurality of mixing modules having a plurality of mixing modules having turbulence generators, wherein the plurality of mixing modules are disposed within a transition duct and an exhaust duct of an exhaust treatment system, in accordance with an embodiment of the present disclosure; A cross-sectional view of the processing system;
3 is an elevation view of the mixing module of FIG. 2 with turbulence generators aligned both vertically and horizontally on the mixing module, in accordance with an embodiment of the present disclosure;
4 is a front view of the mixing module of FIG. 2 with turbulence generators arranged in a staggered arrangement on the mixing module, in accordance with an embodiment of the present disclosure;
FIG. 5 is a cross-sectional view of the exhaust treatment system of FIG. 2 having a plurality of mixing modules, each having turbulence generators in a different arrangement, in accordance with an embodiment of the present disclosure;
6 is a turbulence generator of the mixing module of FIGS. 3 and 4 , in accordance with an embodiment of the present disclosure, comprising fins rotating about an axis oriented substantially parallel to a longitudinal axis of the exhaust treatment system; , a perspective view of the turbulence generator;
7 is a front view of the turbulence generator of the mixing module of FIGS. 2 and 5 comprising corrugated metal packing plates arranged in a plurality of radially extending rows, in accordance with an embodiment of the present disclosure; ego;
8 is a front view of the turbulence generator of the mixing module of FIGS. 2 and 5 comprising corrugated metal packing plates arranged in a single radially extending row, in accordance with an embodiment of the present disclosure; ;
9 is a side view of a non-perforated metal plate that may be used with the corrugated metal packing plates of FIGS. 7 and 8 , in accordance with an embodiment of the present disclosure;
10 is a side view of a perforated metal plate that may be used with the corrugated metal packing plates of FIGS. 7 and 8 , in accordance with an embodiment of the present disclosure; and
11 is a cross-sectional view of a perforated metal plate taken along line 11-11 with holes oriented at different angles, in accordance with an embodiment of the present disclosure.

One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. In the deployment of any such actual implementation, such as in any engineering or design project, a number of implementation specific decisions, such as compliance with system-related and business-related constraints, which may vary from implementation to implementation, are necessary to meet the specific goals of the developers. It should be recognized that it has to be done to achieve it. In addition, it should be appreciated that such development efforts, although complex and time consuming, are the routine tasks of design, fabrication, and manufacture of those of ordinary skill in the art having the benefit of this disclosure nonetheless.

When introducing elements of various embodiments of the invention, the indefinite article, the definite article and “the” are intended to mean that there is more than one element present. The terms “comprising”, “comprising”, and “having” are intended to be inclusive and to mean that there may be additional elements that differ from the listed elements.

Embodiments disclosed herein generally relate to techniques for cooling or mitigating exhaust gas flow. For example, within gas turbine systems, one or more gas turbine engines may combust fuel to produce combustion gases for driving one or more turbine blades. Depending on the type of fuel being combusted, the emissions (eg, exhaust gases) produced from the combustion process include nitrogen oxides (NO _x ), sulfur oxides (SO _x ), carbon oxides (CO _x ) , and unburned hydrocarbons. Often, it will be desirable to reduce the level of these components before the exhaust gases exit a gas turbine system, such as a gas turbine power plant, and while maintaining effective operation of the gas turbine system.

One technique for reducing the amount of removal of NO _x or NO _x in the exhaust gas stream is by selective catalytic reduction (SCR). In the SCR process, a _{reagent such as ammonia (NH 3} ) is injected into the exhaust gas stream _{and NO x} in the exhaust gas and in the presence of a catalyst to produce _{nitrogen (N 2} ) and water (H _{2 O).} react with The effectiveness of the SCR process depends, at least in part, on the temperature of the exhaust gas being treated, which temperature may depend on the particular catalyst used by the SCR system. For example, _{an SCR process to remove NO x} may be particularly effective at temperatures on the order of 500 to 900 degrees Fahrenheit. Thus, if the exhaust gas output from the turbine engine is higher than the effective temperature range for SCR, it would be beneficial to cool the exhaust gases prior to SCR to increase the efficiency of the _{SCR process (eg, removal of NO x ).} will be able

According to embodiments of the present disclosure, a gas turbine system, such as a simple-cycle large gas turbine system, may include an air injection system configured to inject cooling air (eg, air) into an exhaust gas stream. will be. Additionally, the gas turbine system may include a mixing system having a mixing module, including a plurality of turbulence generators that facilitate mixing of the cooling fluid and exhaust gas. As will be described further below, the mixing system may be disposed downstream (ie with respect to the flow of exhaust gases) of the air injection system, but upstream of the SCR system. The turbulence generators of the mixing system may include vortex structures that create a vortex in the flow of the cooling fluid, the exhaust gas, or both, to promote uniform mixing of the cooling fluid and the exhaust gas. In certain embodiments, a gas turbine system may include an arrayed population of mixing modules. Each mixing module in the array population may produce the same or a different vortex pattern. According to these presently disclosed techniques, the mixing system provides improved uniformity of the temperature distribution and/or velocity distribution of the cooled exhaust gas (eg, a mixture of cooling fluid and exhaust gas) received by the SCR system. will be able to provide Also, although the presently disclosed techniques may be particularly useful in simple-cycle large gas turbine systems, as will be discussed below, the technique may be of any suitably configured, including, for example, combined cycle gas turbine systems. It should be understood that it may be implemented within a system.

With the foregoing in mind, FIG. 1 is a schematic diagram of an exemplary turbine system 10 including a gas turbine engine 12 and an exhaust treatment system 14 . In certain embodiments, the turbine system 10 may be all or part of a power generation system. The gas turbine system 10 may use a liquid or gaseous fuel, such as natural gas and/or hydrogen-rich syngas, to drive the gas turbine system 10 .

As shown, the gas turbine engine 12 includes an air intake section 16 , a compressor 18 , a combustor section 20 , and a turbine 22 . The turbine 22 may be dynamically coupled to the compressor 18 via a shaft 24 . In operation, air enters turbine engine 12 through air intake section 16 (indicated by arrow 26 ) and is pressurized within compressor 18 . Air 26 may be provided by one or more air sources 28 (eg, including but not limited to atmosphere). In certain embodiments, air 26 may flow through a filter and/or silencer disposed between compressor 18 and air source 28 . Compressor 18 may include a plurality of compressor stages coupled to shaft 24 . Each stage of compressor 18 includes a wheel having a plurality of compressor blades. Rotation of the shaft 24 causes rotation of the compressor blades, which draws air into the compressor 18 and produces compressed air 30 prior to entry into the combustor section 20. ) is compressed.

The combustor section 20 may include one or more combustors. In an embodiment, a plurality of combustors may be disposed at a plurality of circumferential locations in a generally circular or annular arrangement about the shaft 24 . As compressed air 30 exits compressor 18 and enters combustor section 20 , compressed air 30 may be mixed with fuel 32 for combustion within the combustor. For example, a combustor may include one or more fuel nozzles capable of injecting a fuel-air mixture into the combustor at suitable rates for optimal combustion, emissions, fuel consumption, output, and the like. Combustion of air 30 and fuel 32 may produce hot pressurized exhaust gas 36 (eg, combustion gas), which in turn drives one or more turbine blades inside turbine 22 . It can be used to drive. In operation, combustion gases flowing into and through the turbine 22 flow against and between the turbine blades, thereby driving a load, such as a generator in a power plant, to the turbine blades and to the turbine blades. Accordingly, the shaft 24 is rotationally driven. As discussed above, rotation of shaft 24 also causes the blades inside compressor 18 to draw in and pressurize air received by suction section 16 .

Combustion gases flowing through the turbine 22 will exit the downstream end 40 of the turbine 22 as a stream 42 of exhaust gas. The exhaust gas stream 42 will continue to flow in a downstream direction towards the exhaust treatment system 14 . For example, the downstream end 40 of the turbine 22 may be fluidly coupled to the exhaust treatment system 14 , particularly to the transition duct 50 . In certain embodiments, the exhaust treatment system 14 may include an exhaust diffuser upstream of the transition duct 50 .

As discussed above, as a result of the combustion process, the exhaust gas stream 42 is formed with nitrogen oxides (NO _x ), sulfur oxides (SO _x ), carbon oxides (CO _x ), and unburned hydrocarbons. It may contain certain by-products such as The exhaust treatment system 14 may be employed to reduce or substantially minimize the concentration of such byproducts before the exhaust gas stream exits the system 10 . As mentioned above, one technique for reducing the amount of removal of NO _x or NO _x in the exhaust gas flow, is due to the use of the selective catalytic reduction (SCR) process. For example, in an SCR process for removing _{NO x} from exhaust gas stream 42 _{, ammonia (NH 3} ) is injected into the exhaust gas stream _{and produces nitrogen (N 2} ) and water (H ₂ O). reacts with _{NO x} in the presence of a catalyst for

The effectiveness of such an SCR process may depend, at least in part, on the temperature of the exhaust gas being treated. For example, _{an SCR process to remove NO x} may be particularly effective at temperatures on the order of 500 to 900 degrees Fahrenheit. However, in certain embodiments, the exhaust gas stream 42 exiting the turbine 22 and entering the transition duct 50 may have a temperature of approximately 1000 to 1500°F, or more specifically 1100 to 1200°F. . Accordingly, _{to increase the effectiveness of the SCR process for NO x} removal, the exhaust treatment system 14 is configured to inject cooling air into the exhaust gas stream 42 , thereby causing the exhaust gas stream 42 prior to SCR. may include an air injection system 54 to cool the It should be understood that effective temperatures may vary depending on the element removed from the gas stream 42 and/or the catalyst employed.

As shown in FIG. 1 , an air injection system 54 may be disposed within the transition duct 50 . Air injection system 54 is configured to inject cooling air 58 provided by one or more air sources 28 into transition duct 50 for mixing with exhaust gas stream 42 . It may include a plurality of air jet tubes 56 having jet holes. For example, in one embodiment, the air source 28 may include one or more air blowers, compressors (eg, compressor 18 ), a heat exchanger, or a combination thereof. As will be appreciated, the term “cooling”, when used to describe air flow 58 , means that air 58 is cooler compared to exhaust gas stream 42 exiting turbine 22 . should be understood as For example, the cooling air 58 supplied by the air source 28 may be atmospheric, or may be further cooled using a heat exchanger or other type of suitable cooling mechanism. Air injection system 54 may also include valves for regulating the flow of cooling air 58 . By way of example only, and in one embodiment, exhaust gas stream 42 exiting turbine 22 may flow into transition duct 50 at a rate of approximately 1000 pounds per second, and cooling air 58 may , may be injected (via air injection system 54) into transition duct 50 at a rate of approximately 500 pounds per second. However, it should be understood that the flow rate of the exhaust gas stream 42 and the flow rate of the cooling air 58 may vary. Cooling air 58 is mixed with exhaust gas stream 42 to produce cooled exhaust gas stream 60 . As discussed above, the cooled exhaust gas 60 may have a temperature of approximately 500 to 900 degrees Fahrenheit, ie a temperature suitable to increase or substantially maximize _{NO x removal in the SCR process;} will be able to have As will be discussed further below, the exhaust treatment system 14 provides an exhaust gas stream 42 and cooling air ( mixing systems 64 , 68 along the flow path of the exhaust gas stream 42 , 60 configured to facilitate mixing of 58 .

With continued reference to FIG. 1 , the cooled exhaust gas stream 60 produces a reducing agent 74 (eg, ammonia (NH ₃ )) into the cooled exhaust gas stream 60 . Flow may continue downstream (eg, in direction 46 ) into the exhaust duct 70 , where it may pass through an injection system 72 configured to inject. In one embodiment, the injection system 72 may include a network of pipes, with openings for injecting the reducing agent 74 into the cooled exhaust gas stream 60 . The reducing agent 74 may be vaporized in the evaporator 76 prior to flowing into the injection system 72 .

Downstream of the injection system 72 , the SCR system 80 may include a supported catalyst system having any suitable geometry, such as in a honeycomb or plate configuration. Inside the SCR system 80 , the reducing agent 74 _{reacts with NO x} in the cooled exhaust gas 60 to produce _{nitrogen (N 2} ) and water (H ₂ O), thus resulting in flow arrows ( _{As indicated by 86 , NO x} is removed from the cooled exhaust gas 60 prior to exiting the gas turbine system 10 through the chimney 84 . The chimney 84 may, in some embodiments, include a silencer or muffler. As a non-limiting example, exhaust treatment system 14 may include air injection system 54 , mixing systems 64 to reduce the component _{of NO x in treated exhaust gas stream 86 to approximately 3 ppm or less.} , 68), and the SCR system 80 may be utilized. In another embodiment, atomized water may be mixed with cooling air 58 , and the water-air mixture may be injected into transition duct 50 to lower the exhaust gas temperature.

_{Although this disclosure describes several embodiments that relate to the treatment and removal of NO x} from exhaust gas streams 42 , 60 , certain embodiments may provide for the removal of other combustion by-products, such as carbon monoxide or unburned hydrocarbons. . Accordingly, the catalyst supplied may vary depending on the component being removed from the exhaust gas stream 42 , 60 . Additionally, embodiments described herein are not limited to the use of one SCR system 80 , but may also include multiple SCR systems 80 , multiple catalyst systems, and the like.

To provide control of emissions from system 10 , system 10 also provides continuous emissions monitoring, which continuously monitors the composition of treated exhaust stream 86 exiting chimney 84 . : CEM) system 90 . If the CEM system 90 detects that a component of the treated exhaust stream 86 does not fall within a predetermined set of parameters (eg, temperature, pressure, concentration of specific combustion products), the CEM system 90 ) to adjust operating parameters, perform service, or otherwise shut down the system operation until it can be determined that the treated exhaust stream 86 produced by the system 10 meets regulatory requirements. In order to do so, a notification may be provided to an appropriate regulatory body (eg, an environmental protection organization), which may be responsible for undertaking further action, such as notifying the operators of the system 10 . In some embodiments, CEM system 90 may also specifically treat exhaust, such as adjusting gas turbine flame temperature, flow rate of cooling air 58 , amount of reducing agent 74 injected into duct 50 , and the like. Corrective actions related to the system 14 may be implemented.

Referring now to FIG. 2 , a partial cross-sectional view of an exhaust treatment system 14 is shown, according to one embodiment. Various aspects of exhaust treatment system 14 are described with reference to axial or axial 94 , radial or axial 96 , and circumferential or axial 98 for gas turbine engine and exhaust duct 70 . it could be For example, axis 94 corresponds to a longitudinal axis 100 or a longitudinal direction of a gas turbine engine, and axis 96 corresponds to a direction orthogonal or radial to longitudinal axis 100 , and axis 98 corresponds to a circumferential direction about axial axis 94 (eg, longitudinal axis 100 ). The upstream end 104 of the transition duct 50 may include an opening 106 that fluidly couples the transition duct 50 to the turbine 22 to receive an exhaust gas stream 42 . . FIG. 2 additionally shows an embodiment of mixing systems 64 , 68 disposed within the transition duct 50 and exhaust duct 70 , respectively. The mixing systems 64 , 68 are arranged between a first wall 116 and a second wall 118 of the exhaust treatment system 14 in a radial direction 96 and circumferentially about a longitudinal axis 100 . It may include a plurality of turbulence generators 110 , 112 , arranged at 98 . Walls 116 , 118 define passageway 120 through which exhaust gas flow 42 and cooling fluid 58 flow from transition section 50 to exhaust duct 70 .

Mixing systems 64, 68 include one or more mixing modules 124 comprising turbulence generators 110, 112 arranged in series and/or in a staggered arrangement with respect to adjacent turbulence generators 110, 112. could include As exhaust gas 42 and cooling air 58 flow through mixing modules 124 , the flow of exhaust gas 42 and cooling air 58 becomes laminar as shown by arrow 125 . From there, there may be a transition to turbulence as shown by arrow 127 . The turbulence 127 of exhaust gas 42 and cooling air 58 may promote uniform mixing of exhaust gas 42 and cooling air 58 .

In certain embodiments, the mixing system 64 may include a plurality of mixing modules 124 . For example, returning to FIG. 2 , the illustrated mixing system 64 may include an arrayed population of modules 124 arranged in stages at different locations along the longitudinal axis 100 . In the illustrated embodiment, three mixing modules 124 (eg, three mixing stages) are shown. However, mixing system 64 may include any suitable number of mixing modules 124 . For example, the mixing system 64 may include 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, or 100 mixing modules 124 .

Transition duct 50 expands generally in a downstream direction 46 . As a non-limiting example, the upstream end 104 of the transition duct 50 has a dimension 142 and the opposite downstream end 146 of the transition duct 50 is of the upstream end 104 . may have a dimension 148 , which may be between approximately 10% and approximately 75% larger than dimension 142 . In certain embodiments, each mixing module 124 may have a different dimension 150 to account for the increase in the size of the flow path of exhaust gas 42 and cooling air 58 . For example, the dimension 150 of each module 124 may increase in the downstream direction 46 to match the expanded configuration of the transition duct 50 . In other words, the dimension 150 of the mixing module 124 closest to the upstream end 104 may be smaller than the dimension 150 of the mixing module 124 closest to the downstream end 146 . In a particular embodiment, the dimension 150 of each mixing module 124 is such that, for example, the dimensions 142 , 148 of the transition duct 50 are the same or the mixing modules 124 are connected to the wall 116 . In embodiments that do not extend to , it may be the same.

The array of mixing modules 124 may be arranged such that each module 124 is disposed adjacent the air jet tube 56 of the air jet system 54 . For example, in a particular embodiment, the air jet tubes 56 may be arranged in progressively different vertical and horizontal positions along the longitudinal axis 100 . Each air jet tube 56 depends on various factors, such as the size of the transition duct 50 , the required number of mixing zones inside the transition duct 50 , and the size of the mixing modules 124 , among others. It may be spaced from an adjacent air jet tube 56 by a dimension 156 . Accordingly, one of the mixing modules 124 may be disposed within the space between each air jet tube 56 . By disposing each mixing module 124 of the array population between each air jet tube 56, the mixing modules 124 improve mixing between the exhaust gas stream 42 and the cooling air 58, It makes it possible to cause a uniform temperature distribution of the cooled exhaust gas 60 . That is to say, the mixing modules 124 and the air jet tubes 56 may be interposed between each other to form jetting and mixing stages within the transition duct 50 .

For example, the flow characteristics of the exhaust gas and cooling air mixture may be iteratively changed by each mixing module 124 as the mixture flows in the downstream direction 46 . Iterative alteration of the flow properties of the mixture promotes turbulence within the mixture, thereby promoting uniform distribution of exhaust gas flow 42 and cooled air 60 and exhaust gas within transition duct 50 . (42) is allowed to cool. Accordingly, the cooled exhaust gas 60 may be sufficiently cooled to a required temperature for effective SCR processing, and may also have a uniform temperature distribution. The uniform temperature distribution of the cooled exhaust gas 60 may increase the effectiveness of the SCR process for removal of _{combustion by-products (eg, NO x ).}

As discussed above, the SCR process may depend, at least in part, on the temperature of the exhaust gas. During cooling of the exhaust gas within the transition duct 50 , the cooling air 58 may not be evenly distributed within the exhaust gas stream. Non-uniform mixing of exhaust gas and cooling air may create localized zones of hot exhaust gas (eg, hot spots) within the cooled exhaust gas. Localized zones of these hot exhaust gases may not be brought to a suitable temperature for the SCR process, thereby reducing the effectiveness of the SCR process. However, by using the mixing modules 124 to change and disperse the flow characteristics of the exhaust gas flow 42 , the cooling air 58 , or both, the exhaust gas flow The mixing efficiency of 42 ) and cooling air 58 may be improved compared to systems that do not include mixing systems 64 , 68 .

Additionally, due to the improved mixing of the exhaust gas stream 42 and the cooling air 58, the cooled exhaust gas 60 may have a uniform temperature distribution suitable for effective SCR treatment of the exhaust gas. will be.

In the illustrated embodiment, the mixing modules 124 of the mixing system 64 are sandwiched between the air jet tube 56 and each other, although in other embodiments, all of the mixing modules 124 or the mixing module 124 are ) may be disposed upstream of the air injection system 54 . For example, the mixing system 64 may be disposed between the opening 106 and the air jet system 54 (eg, upstream of the first air jet tube 56 of the air jet system 54 ). will be able The mixing modules 124 may swirl the exhaust gas stream 42 in multiple directions as the exhaust gas stream 42 exits the turbine 22 and enters the transition duct 50 . The vortex of the exhaust gas stream 42 may further promote turbulence and may distribute the exhaust gas stream 42 through the passageway 120 . The mixing modules 124 may include a plurality of corrugated packing plates configured to swirl air, exhaust gas, or both, at least in a first vortex direction. This dispersion of the exhaust gas stream 42 may facilitate cooling by dispersing the exhaust gas stream 42 within the exhaust treatment system 14 , which causes the cooling air 58 to 42 may allow cooling the exhaust gas stream 42 more efficiently as compared to systems that are not evenly distributed within the transition duct 50 .

In certain embodiments, exhaust treatment system 14 may include a mixing system downstream of transition duct 50 . For example, as shown in FIG. 2 , the mixing system 68 is disposed inside the exhaust duct 70 . The mixing system 68 may be disposed upstream of the injection system 72 adjacent to the injection system 72 . The placement of the mixing system 68 adjacent the injection system 72 may improve the effectiveness of the SCR process for removing combustion by-products. For example, as discussed above, cooled exhaust gas 60 flows from transition duct 50 to exhaust duct 70 , where the cooled exhaust gas reacts with reducing agent 74 . . As the cooled exhaust gas 60 moves away from the mixing module 124 and continues to flow through the transition duct 50 , the flow of the cooled exhaust gas 60 may transition from turbulent flow back to laminar flow. Accordingly, it may be desirable to include the mixing system 68 in the exhaust duct 70 adjacent the injection system 72 . Accordingly, the mixing system 68 can change laminar flow to turbulent flow and disperse the cooled exhaust gas 60 as the cooled exhaust gas flows into the exhaust duct 70 , thereby allowing the cooled exhaust gas to flow into the exhaust duct 70 . It promotes uniform mixing of the exhaust gas 60 with the reducing agent 74 . Thus, the reaction between the reducing agent 74 and combustion by-products (eg, NO _x ) in the cooled exhaust gas 60 does not involve a mixing system such as the mixing system 68 inside the exhaust duct 70 . Compared to systems that do not, it can be improved. As a result, the efficiency of the SCR process may also be improved.

For example, FIG. 3 shows turbulence generators 110 , 112 disposed along dimension 126 of module 124 at various vertical and horizontal positions with respect to centerline axis 130 of mixing module 124 . The mixing module 124 of the mixing system 64 , 68 is shown. The centerline axis 130 of the mixing system 64 , 68 indicates that the vertical and horizontal positions of the turbulence generators 110 , 112 are circumferential 98 and radial 96 about the longitudinal axis 100 . may intersect (eg, orthogonal) with the longitudinal axis 100 of the exhaust treatment system 14 . Module 124 includes a plurality of support beams 128 oriented parallel to or intersecting (eg, orthogonal, such as horizontal) to centerline axis 130 . The support beams 128 may intersect at various points 132 along the dimension 126 to form a mesh-like support structure. Module 124 may include any suitable number of support beams 128 to support turbulence generators 110 , 112 . Each of the support beams 128 may be spaced apart from an adjacent one support beam 128 in both the vertical and horizontal directions with respect to the centerline 130, whereby the exhaust gas stream 42, cooling air ( 58), or both, to form passages 134 through which it can flow. As shown in FIG. 3 , turbulence generators 110 , 112 may be disposed at respective intersection points 132 of module 124 . Accordingly, each turbulence generator 110 , 112 may be aligned with another turbulence generator 110 , 112 in an adjacent support beam 128 .

In another embodiment, as shown in FIG. 4 , turbulence generators 110 , 112 are staggered on module 124 (eg, staggered with respect to the radial direction of gas turbine engine 12 ). will be able to provide For example, in the illustrated embodiment, the turbulence generators 110 , 112 in the first row 138 may be disposed at intersection points 132 along the centerline axis 130 and in the second row 140 . ) turbulence generators 110 , 112 may be biased from intersection points 132 along centerline axis 130 . Accordingly, the turbulence generators 110 , 112 in the first row 138 may not be in line with the turbulence generators 110 , 112 in the second row 140 .

As discussed above, the mixing system 64 disposed within the transition duct 50 is arranged in any horizontal position along the longitudinal axis 100 of the exhaust treatment system 14 , the mixing modules 124 . ) may be provided with an array of groups. The mixing system 68 disposed within the exhaust duct 70 may also have a similar arrangement. FIG. 5 shows an embodiment of an arrayed population 170 of mixing modules 124 , which may be disposed within a transition duct 50 or an exhaust duct 70 . The array population 170 may include any suitable number of mixing modules 124 . For example, sequence population 170 can be 2, 3, 4, 5, 10, 15, such as between 2 and 100, between 2 and 50, between 2 and 20, between 2 and 10, between 4 and 6, etc. , 20, 30, 40, 50, 80, or 100 mixing modules 124 . The mixing modules 124 in the array population 170 are configured such that the turbulence generators 110 , 112 of the mixing module 124 are adjacent to the turbulence generators 110 , 112 of each mixing module 124 in the array population 170 . ) and may be arranged to lie on a straight line. In other words, array population 170 may include mixing modules 124 , in which turbulence generators 110 , 112 have identical individual locations on module 124 . In other embodiments, each mixing module 124 in array population 170 may have a different array of turbulence generators 110 , 112 . For example, as shown in FIG. 5 , mixing modules 124 have different arrangements of turbulence generators 110 , 112 . Staggering the turbulence generators 110 , 112 in this way may help reduce regions of laminar flow within the ducts 50 , 70 . Accordingly, the turbulence generators 110 , 112 of one mixing module 124 have a staggered arrangement with respect to the turbulence generators 110 , 112 of an adjacent mixing module 124 .

The operation of the turbulence generators 110 , 112 may be further appreciated with reference to FIG. 6 , which is a perspective view of the turbulence generator 110 , 112 and a portion of the mixing module 124 . In the illustrated embodiment, the turbulence generators 110 , 112 have a central ring 176 through which the exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 can flow. ) (eg, a ring). The center ring 176 includes pins extending radially away from the center ring 176 in 96 . The pins 178 may be spaced apart in a circumferential direction 98 along the perimeter of the central ring 176 . In the illustrated embodiment, the turbulence generators 110 , 112 include three pins 178 . However, the turbulence generators 110 , 112 may include any number of pins 178 . For example, the turbulence generator may include 2, 3, 4, 5, 6, 7, 8, 9, 10, 20 or more, such as between 2 and 20, between 2 and 10, between 2 and 6, etc. It may include a pin 178 .

The turbulence generators 110 , 112 are configured in a circumferential direction 98 in a direction 180 ( For example, it may be configured to rotate in a clockwise direction. The tips of the fins 178 are designed to facilitate rotation of the turbulence generators 110 , 112 (eg, to reduce drag on the turbulence generators 110 , 112 during rotation) and of the fins 178 . It may be curved in direction 180 to reduce low flow regions immediately downstream. In other embodiments, turbulence generators 110 , 112 may rotate in a direction substantially opposite to direction 180 (eg, counterclockwise). In certain such embodiments, the tip of the fins 178 may be curved in a direction substantially opposite to direction 180 . Additionally, the fins 178 may have a twist angle of between approximately 5 degrees and approximately 75 degrees.

In another embodiment, the turbulence generators 110 , 112 may include corrugated (eg, raised, grooved) packing plates. For example, FIGS. 7 and 8 show front views of corrugated packing plates 184 , 186 , which may be used in mixing module 124 , respectively. Corrugated packing plates 184 , 186 comprise layers of metal plates 190 having a corrugated surface. Metal plates 190 are created, in part, when exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 collides with the corrugated surfaces of metal plates 190 . The resulting turbulence may promote heat transfer and uniform distribution of exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 .

The metal plates 190 may be arranged in rows 194 extending radially 96 by at least a portion of the dimension 196 of the corrugated packing plate 184 . For example, as shown in FIG. 7 , rows 194 extend radially along dimension 196 in substantially the same radial direction 96 . However, in other embodiments, the rows 194 may extend radially across a portion of the dimension 196 in different radial directions 96 . For example, the corrugated packing plate 186 shown in FIG. 8 has a set of rows 194 extending in one radial direction 96 (a first radial direction) and a set of rows 194 extending in a different radial direction 96 (a first radial direction). and another set of rows 198 extending in a second radial direction different from the radial direction. Accordingly, the columns 194 may be oriented at an angle (eg, perpendicular or at an acute angle) with respect to the columns 198 . While each plate 190 shown in FIG. 8 includes ridges (eg, grooves) oriented at different angles with respect to the axis 94 , the plates 190 as a whole, approximately in one direction. is extended

Rows 194 , 198 are formed on each metal plate, allowing exhaust gas flow 42 , cooling air 58 , and/or cooled exhaust gas 60 to flow through corrugated packing plate 184 . 190) to form passages 200 between them. As a fluid (eg, exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 ) flows through passageways 200 , the fluid 112 ) collides with the corrugated surface of the metal plates 190 , which can change the direction of flow inside and consequently create turbulence.

Corrugated packing plates 184 , 186 may include non-perforated plates, perforated plates, or both. For example, FIG. 9 shows that to be used in corrugated packing plates 184 , 186 to vary the flow characteristics of exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 . A side view of the non-perforated metal plate 204 is shown. The non-perforated metal plate 204 may block fluid flowing through the corrugated packing plates 184 , 186 from flowing into adjacent rows 194 , 198 while promoting turbulence within the passageways 200 . will be able That is to say, the arrangement shown in FIG. 9 may create a plurality of zones of turbulence.

FIG. 10 may also be used in corrugated packing plates 184 , 186 to change the flow characteristics of exhaust gas stream 42 , cooling air 58 , cooled exhaust gas 60 , or a combination thereof. A side view of an embodiment of a perforated metal plate 208 is shown. The perforated metal plate 208 may include one or more apertures 210 distributed at various axial 94 and radial 96 positions with respect to the axis 212 of the perforated metal plate 208 . . The apertures 210 extend axially 94 and radially 96 along at least a portion of the dimensions 214 , 216 , respectively, of the perforated metal plate 208 . For example, in the illustrated embodiment, the apertures 210 extend from the plate upstream end 218 to the plate downstream end 220 . The apertures 210 allow fluid (eg, exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 ) to flow along and through metal plates 190 . to allow fluid communication between the passageways 200 of the corrugated packing plates 184 , 186 . This may promote uniform mixing of the fluids as they flow through the mixing systems 64 , 68 , and uniform temperature distribution within the cooled exhaust gas 60 .

The perforated metal plate 208 may also include a perforated portion 224 and a non-perforated portion 226 . Portions 224 and 226 may be arranged in any suitable pattern. As shown in FIG. 10 , portions 224 , 226 alternate radially 96 along dimension 216 . Accordingly, each perforated portion is adjacent to the non-perforated portion 226 . However, in other embodiments, a plurality of perforated portions 224 and/or non-perforated portions may be adjacent to each other. The particular arrangement of portions 224 , 226 may provide a desirable change in the flow properties of the fluid to enable uniform mixing within and downstream of the corrugated packing plates 184 , 186 .

In certain embodiments, the apertures 210 of the perforated plate 208 may have a constant or variable dimension along the axis 212 (eg, the apertures are annular). The diameter may gradually increase or decrease from the first plate end 218 to the second plate end 220 or vice versa. The diameter of the holes 210 may also increase or decrease along axis 212 towards both plate ends 218 , 220 . Additionally, the holes may be oriented at an angle with respect to the axis 212 . For example, FIG. 11 shows a cross-sectional view of a portion of the perforated metal plate 208 along line 11-11. In the illustrated embodiment, the holes 210 of the perforated metal plate 208 are oriented at different angles (perpendicular or inclined at an acute angle to the axis 212 ). The oblique orientation of the apertures 210 allows the fluid (eg, exhaust gas stream 42 , cooling air 58 , and/or cooling) as the fluid flows through the corrugated packing plate 184 , 186 . It may be possible to increase the mixing and heat transfer efficiency of the exhaust gas 60 ). For example, the beveled aperture 210 allows the flow of fluid as it flows across the perforated metal plate 208 into adjacent passageways 200 and impinges on the corrugated surface of the metal plate 190 . You can change direction. A change in the flow direction of the fluid can enhance the turbulence created when the fluid impinges on the corrugated surfaces, thereby resulting in a uniform mixing of the fluid (eg, exhaust gas stream 42 , cooling air 58 ). ), cooled exhaust gas 60, and a mixture of reducing agent 74). Accordingly, the effectiveness of the SCR process for removing combustion by-products (eg, NO _x ) is, compared to systems that do not include mixing systems 64 , 68 within the exhaust treatment system 14 , could be improved

Any of the embodiments described herein may be used in any suitable combination to achieve desirable heat transfer and fluid flow properties. For example, as discussed above with reference to FIGS. 3 and 4 , mixing module 124 includes a plurality of turbulence generators 110 , 112 arranged in different vertical and horizontal positions along dimension 126 . will be able to provide In certain embodiments, each turbulence generator 110 , 112 of mixing module 124 promotes different flow characteristics of exhaust gas stream 42 , cooling air 58 , and/or cooled exhaust gas 60 . You can do it. For example, referring to FIG. 6 , the turbulence generators 110 , 112 may rotate about the longitudinal axis 100 of the exhaust treatment system 14 . In a particular embodiment, the turbulence generators 110 , 112 may rotate in the same direction (eg, direction 180 (clockwise) or a direction opposite to direction 180 (counterclockwise)). will be. In another embodiment, some of the turbulence generators 110 , 112 of the mixing module 124 may rotate in the direction 180 (eg, clockwise) and another of the turbulence generators 110 , 112 . Some may rotate in a direction substantially opposite to direction 180 (eg, counterclockwise).

Similarly, the turbulence generators 110 , 112 of each module 124 in the array population 170 (see FIG. 5 ) of the mixing system 68 , 64 , the adjacent mixing module 124 in the array population 170 . may be rotated in the same direction as or in a different direction. As an example, the mixing module 124 closest to the upstream end 104 of the transition duct 50 may rotate in the direction 180 (eg, clockwise), and backward in the downstream direction 46 . The following mixing module 124 may rotate in a direction substantially opposite to direction 180 (eg, counterclockwise). Varying the direction of rotation (eg, direction 180 ) of the turbulence generators 110 , 112 ensures that the exhaust gas stream 42 and cooling air 58 are uniformly mixed and the exhaust treatment system 14 . It may create turbulence within the exhaust treatment system 14 to be distributed throughout. In this way, a uniform temperature distribution within the cooled exhaust gas 60 may be achieved. In addition, the cooled exhaust gas 60 is a system that does not use the mixing system 64 because the cooling air 58 can be effectively mixed with the exhaust gas stream 42 by using the mixing system 64 . Compared to the above, it may be cooled to a suitable temperature for effective removal of combustion by-products (eg, NO _{x ) within the SCR system 80 .} Additionally, the variable rotation of the turbulence generators 110 , 112 within a single mixing module 124 within the mixing system 68 or between the mixing modules 124 within the array population 170 may result in an exhaust duct 70 may allow for uniform mixing between the cooled exhaust gas 60 and the reducing agent 74 inside (eg, via the mixing system 68 ), thereby causing the exhaust duct 70 interior Compared to systems that do not include mixing modules 124 in the

In a particular embodiment, the mixing modules 124 may include different types of turbulence generators 110 , 112 . For example, one mixing module 124 in the array population 170 may use the rotary turbulence generators shown in FIG. 6 , and the other mixing module 124 in the array population 170 may have a corrugated packing. Plates 184 and 186 may be used. In other embodiments, different types of turbulence generators 110 , 112 may be placed within a single mixing module 124 . For example, some of the turbulence generators 110 , 112 of the mixing module 124 may be a corrugated packing plate 184 , 186 and some of the turbulence generators 110 , 112 of the mixing module 124 . may be rotary turbulence generators (see, eg, FIG. 6 ). Having different types of turbulence generators 110 , 112 within the array population 170 and/or each mixing module 124 results in a cooled exhaust gas 60 prior to entering the SCR system 80 . desirable for effectively distributing and mixing the exhaust gas stream 42 , the cooling air 58 , and/or the cooled exhaust gas 60 within the exhaust treatment system 14 , resulting in a uniform temperature distribution of It can create turbulence.

As discussed above, various techniques described herein can be used to improve the uniformity of the temperature and/or velocity distribution of an exhaust gas stream, while also cooling the exhaust gas stream to improve the efficiency of the selective catalytic reduction process. It may be possible to provide a mixture of exhaust gas flow and cooling air for this purpose. For example, the techniques disclosed herein may cover any combination of mixing modules and turbulence generator configurations for changing exhaust gas flow, cooling air, and/or flow characteristics of the cooled exhaust gas. Changes in the flow characteristics of the exhaust gas, cooling air, and/or cooled exhaust gas may create turbulence, which may facilitate mixing and cooling of the exhaust gas stream exiting the gas turbine engine. The disclosed techniques and configurations for the mixing system 64 , 68 are intended to be merely examples of specific embodiments, and should not be construed as limiting in any way.

This written description is intended to disclose the present invention, including the best mode, and also includes making and using any apparatus or systems and practicing any integrated methods by any person skilled in the art. To make it possible to practice the present invention, examples are used. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Other such examples are the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. It is intended to fall within

Claims (20)

A simple-cycle gas turbine system comprising:
An injection system comprising a plurality of injection tubes configured to inject a fluid into a duct of an exhaust treatment system configured to treat exhaust gas generated by a gas turbine engine, the exhaust treatment system comprising: an injection system disposed within and comprising a selective catalytic reduction (SCR) system configured to reduce the level of nitrogen oxides (NO _{x ) in the exhaust gas;} and
A mixing system disposed within the exhaust treatment system, the mixing system comprising: a first vortex direction to promote turbulence along an axis of the exhaust treatment system and thereby enable mixing between the fluid and the exhaust gas wherein the mixing system comprises a mixing module having a grid comprising a plurality of rotary turbulence generators configured to swirl the fluid, or the exhaust gas, or both.
including,
the mixing module is arranged such that each of the rotary turbulence generators of the plurality of rotary turbulence generators is arranged at a different position relative to another rotary turbulence generator along a horizontal direction or a vertical direction of the mesh, the gas turbine engine and the exhaust duct a respective rotary turbulence generator of the plurality of rotary turbulence generators disposed in a transition duct of the exhaust treatment system positioned therebetween, the horizontal direction or the vertical direction intersecting the axis; and a shaft configured to rotate about the axis. The method of claim 1,
wherein the mixing module is a first mixing module, the plurality of rotary turbulence generators are a first plurality of rotary turbulence generators, and the mixing system is disposed downstream of the first mixing module and is a first in the exhaust treatment system. and a second mixing module having a second plurality of rotary turbulence generators configured to swirl the fluid, or the exhaust gas, or both, in two vortex directions. 3. The method of claim 2,
and the first vortex direction and the second vortex direction are the same. 3. The method of claim 2,
and the first vortex direction and the second vortex direction are different. 3. The method of claim 2,
wherein the first plurality of rotary turbulence generators and the second plurality of rotary turbulence generators are aligned along a longitudinal axis of the exhaust treatment system. 3. The method of claim 2,
wherein the first plurality of rotary turbulence generators and the second plurality of rotary turbulence generators are arranged in a staggered arrangement along a longitudinal axis of the exhaust treatment system. 3. The method of claim 2,
wherein the first mixing module, the second mixing module, or both are disposed between the injection tubes of the plurality of injection tubes. The method of claim 1,
Each of the rotary turbulence generators of the plurality of rotary turbulence generators includes a plurality of fins extending in a radial direction from a center of the rotary turbulence generator, wherein the fins of the plurality of fins in the first vortex direction; and is configured to rotate about a longitudinal axis of the exhaust treatment system. The method of claim 1,
wherein the mixing module comprises a plurality of corrugated packing plates configured to swirl air, the exhaust gas, or both, at least in the first vortex direction. 10. The method of claim 9,
wherein the corrugated packing plates are perforated. The method of claim 1,
wherein the injection system is configured to inject cooling air as a fluid into the transition duct, the transition duct is fluidly coupled to a turbine of the gas turbine engine, and the mixing module is configured to: wherein the simple-cycle gas turbine system is configured to promote turbulence of gas and the cooling air, thereby facilitating mixing and heat exchange between the cooling air and the exhaust gas. The method of claim 1,
the injection system is configured to inject a reducing agent as the fluid into the exhaust duct containing a catalyst of the SCR system, a second mixing module of the mixing system disposed within the exhaust duct, the second mixing module is configured to promote turbulence of the exhaust gas and the reducing agent along the axis of the exhaust treatment system, thereby facilitating mixing between the reducing agent and the exhaust gas. A simple-cycle large gas turbine system comprising:
a mixing system disposed within an exhaust treatment system of a simple-cycle large gas turbine system;
The mixing system is:
a first having a first plurality of rotatable turbulence generators configured to swirl, in a first vortex direction, cooling air, an exhaust stream produced by a large gas turbine engine of a simple-cycle large gas turbine system, or both a first mixing module comprising a network; and
a second mixing module including a second mesh having a second plurality of rotatable turbulence generators configured to swirl the cooling air, the exhaust stream, or both, in a second vortex direction
including,
The first mixing module, the second mixing module, or both may be configured such that the first and second plurality of rotary turbulence generators are positioned at different positions relative to other rotary turbulence generators along a horizontal direction or a vertical direction of each mesh. arranged in a transition duct of the exhaust treatment system, wherein the horizontal direction or the vertical direction intersects a flow direction through the exhaust treatment system, the rotational turbulence of the first and second plurality of rotary turbulence generators wherein each of the generators includes a shaft configured to rotate the rotary turbulence generator about a longitudinal axis of the exhaust treatment system. 14. The method of claim 13,
A simple-cycle large gas turbine system further comprising an air jet system comprising a plurality of air jet tubes configured to supply the cooling air to a transition section. 15. The method of claim 14,
wherein the first mixing module, the second mixing module, or both are disposed between the air jet tubes of the plurality of air jet tubes. 14. The method of claim 13,
and the first vortex direction and the second vortex direction are the same. 14. The method of claim 13,
and the first vortex direction and the second vortex direction are different. 14. The method of claim 13,
wherein the first plurality of rotary turbulence generators and the second plurality of rotary turbulence generators are aligned along a longitudinal axis of the exhaust treatment system. 14. The method of claim 13,
wherein the first plurality of rotary turbulence generators and the second plurality of rotary turbulence generators are arranged in a staggered arrangement along a longitudinal axis of the exhaust treatment system. A method for treating exhaust gases in a simple-cycle gas turbine system, comprising:
flowing an exhaust stream from the gas turbine engine into a transition section of an exhaust treatment system;
injecting cooling air into the flow of exhaust stream in the transition section using an air injection system comprising a plurality of air injection tubes configured to inject cooling air;
swirling the exhaust stream, or the cooling air, or both, within a transition section of the exhaust treatment system using a mixing system having an array population of mixing modules; each module comprising: a mesh having a plurality of rotary turbulence generators configured to swirl the exhaust stream, the cooling air, or both, in a first direction, a second direction, or both; Vortexing the exhaust gas, the cooling air, or both, mixes the exhaust stream and the cooling air within the exhaust treatment system to produce a cooled exhaust gas and heat between the exhaust stream and the cooling air the exhaust stream, or the cooling air; or swirling both;
directing the cooled exhaust gas to a selective catalytic reduction (SCR) system; and
reducing the level of _{nitrogen oxides (NO x} ) in the cooled exhaust gas using the SCR system;
A method for treating exhaust gases, comprising:

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